In the fuel tank for an automobile, there is publicly known a technology wherein a tip of a refueling pipe connecting a refueling opening and the fuel tank is projected into the fuel tank, and a check valve (ICV: inlet check valve) is provided at an projected end thereof to suppress a backflow of a fuel liquid and fuel steam inside the fuel tank into a refueling opening side (for example, Patent Document 1).
A fuel tank check valve described in the Patent Document 1 comprises a cylindrical member (pipe); a flap (valve member) axially supported on the cylindrical member; and a torsion coil spring (spring) urging the flap in a closing direction. A pivot (supporting shaft) supporting the flap to open and close includes a tip portion inserted into a receiving hole provided in the cylindrical member; and an enlarged diameter portion on which a coil portion of the torsion coil spring is mounted. The enlarged diameter portion is provided so as to reduce a gap between an inner periphery of the coil portion and the pivot, and the pivot can hold the torsion coil spring without rattling.